Field of the Invention
The invention relates to devices for raising cargo container handling cranes and particularly to a system for installation of a jacking tower on a cargo container handling crane for lifting portions of the crane to facilitate increasing the height of the crane.
Description of Related Art
Jacking towers are used to modify cranes, in particular to lift separated portions of a crane in order to facilitate crane raise modifications. A jacking tower must be installed on the sill beams of the crane in order to lift a separated upper portion of the crane to permanently increase the height of a crane. Jacking towers are typically large and heavy. Therefore, a method of efficiently moving a partially or fully assembled jacking tower on and off the crane is desirable to reduce job time and expense.
FIG. 1 shows a typical situation where a jacking tower 12 is in position for being moved onto a container crane 4. To install a fully assembled jacking tower onto a crane, the jacking tower must be lifted over and lowered onto the sill beams 6 of the crane 4. Traditionally, this is accomplished by using dedicated lifting cranes, which are expensive to procure and operate. Alternatively, jacking towers can be assembled directly on the crane, but this is time-consuming and requires that the crane be taken out of service for an extended time.
The jacking tower installation system described below provides a simple, fast, and cost-effective system and method for installing and uninstalling jacking towers on cargo container cranes to facilitate crane raise operations.